Electrical computers and digital processing systems: virtual mac – Virtual machine task or process management
Reexamination Certificate
2000-05-10
2004-10-05
Follansbee, John (Department: 2154)
Electrical computers and digital processing systems: virtual mac
Virtual machine task or process management
C719S319000
Reexamination Certificate
active
06802062
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates to a virtual machine system constituting a loosely-coupled multiprocessor system including a plurality of real machines, or more in particular to a method for controlling the movement of an operating system working for a virtual machine system on a given real machine to a virtual machine system on another real machine, and a virtual machine system for realizing the transfer of the operating system working for a virtual machine system on a given real machine to a virtual machine system on another real machine.
An example of a system using a machine will be explained with reference to FIG.
12
.
FIG. 12
is a block diagram showing a general configuration of a virtual machine system based on a loosely-coupled multiprocessor system. The loosely-coupled multiprocessor system (LCMP) shown in
FIG. 12
comprises real machine resources
13
including common resources such as a magnetic disk unit
131
and a magnetic tape unit
132
shared by a plurality of real machines (also called the bare machines), and information transmission means
12
connecting the real machines
10
,
11
.
In the loosely-coupled multiprocessor system (LCMP), a configuration of a machine system with a computer virtually arranged on each of the real machines
10
,
11
, i.e. a virtual machine system in operation will be explained with reference to FIG.
12
. The virtual machine system provided for each of the real machines
10
,
11
, is realized by controlling the real machines
10
,
11
in accordance with virtual machine control programs (VMCP)
101
,
112
. Specifically, the real machines
10
,
11
are controlled by the VMCPs
101
,
112
in such a manner that an instruction processor, a main memory, an extended memory and an input/output unit of the real machine can be used as virtual resources. The virtual machine system included in each of the real machines
10
,
11
, under the control of the VMCPs
101
,
112
, applies an input/output signal to a console
14
and a spool file
15
connected to the virtual machine system in another real machine through the information transmission means
12
.
Once the virtual machines (VM)
102
,
103
are generated in the virtual machine system arranged on the real machine
10
, however, the particular VMs are fixed in the virtual machine system. In other words, the VMs
102
,
103
are fixed in the real machine
10
and cannot be moved to another virtual machine VM
113
, for example, arranged on another real machine
11
. As a result, the following restrictions are imposed on the operation and management of the system.
(1) In the case where the number of the VMs in operation or the use of the main memory, the extended memory, the instruction processor (IP), the input/output channel or other machine resources by the operating system (OS) of the VM increases only for a specific real machine in the LCMP, then, the load is undesirably concentrated on the particular real machine. The result is that the operating system of the VM arranged on the particular specific real machine cannot enjoy a sufficient service. The operating system on the VM arranged on the particular specific real machine cannot use other real machine resources lower in utility rate.
(2) Also in the case where the operation of a given real machine is intentionally suspended with the aim of providing hardware maintenance of the real machine, the fact that the VM is fixed to the real machine makes it necessary to suspend the operation of the operating system on the VM arranged on the real machine to be stopped.
(3) In either case of (1) or (2) above, for the machine resources of other real machines to be used, the operation of the operating system on the VM arranged in the real machine has to be suspended, a new VM has to be generated in another real machine and the operating system on the VM arranged on the first real machine has to be reactivated.
As described with reference to
FIG. 12
, a VM, once generated, cannot be moved to the VM on a virtual machine system operating with another real machine as long as the operating system for the first VM is in operation. The following problems are encountered if the operation of an operating system is to be continued by moving the VM of the virtual machine system on one real machine to the VM of the virtual machine system on another real machine while the operation of the operating system for the first VM is going on.
(1) The first problem concerns the VM configuration of the origin system and destination system.
In an operating system, a hardware configuration is recognized at the time of activating the operating system, and the configuration information thereof is retrieved and managed in the main memory. Assume that the VM
103
on the real machine
10
is moved as a VM
113
on a real machine
11
in
FIG. 12
, for example, and that a difference exists between the origin VM
103
and the destination VM
113
in the capacity of the virtual memory or the virtual extended memory of the VM, the number of IPs or the input/output configuration. The resulting problem is that a difference develops between the hardware configuration on the VM which has thus far been managed by the origin OS
105
in the main memory and the VM hardware configuration of the destination OS
115
, thereby leading to the failure to guarantee the operation of the OS
115
. It is also necessary to assign the destination VM
113
with the same real machine resources as the real machine resources
13
shared and controlled in the virtual machine system by the LCMP assigned to the origin VM
103
. Especially for the input/output configuration, what is called the extended channel system (ECS) is assigned a subchannel in one-to-one relation with an input/output unit regardless of the connection between the channel and the input/output unit (device). The program operating on the VM issues a start subchannel (SSCH) by designating a subchannel number corresponding to the device and an operation request block (ORB)
30
as described later and shown in FIG.
2
. Specifically, it is necessary not only that the same real machine resources as the input/output unit, the magnetic disk unit
131
and the magnetic disk tape unit
132
constituting the real machine resources
13
shared in the LCMP assigned to the origin VM
103
are assigned to the destination VM
113
, but also that the subchannels corresponding to the input/output units for the destination VM
113
are arranged the same way as those of the origin VM
103
. Also, it is possible to read a path management control word (POMC)
31
and a subchannel status word (SCSW)
32
of each subchannel as shown in
FIG. 2
from the program in response to a store subchannel (STSCH). The path management control word (PMCW)
31
has stored therein the input/output route information to the input/output unit used by a particular subchannel, including a path installed mask (PIM), a path available mask (PAM) and physical addresses CHP
1
D
0
to CHP
1
DP of the channels. These input/output route information are also required to be identical between the origin VM
103
and the destination VM
113
.
(2) The second problem concerns the VM stop and restart
As long as the operating system is working, the virtual resources represented by the main memory may be updated, so that information cannot be moved to another machine with the operating system working on the particular information. Specifically, for the VM to be moved, it is necessary to suspend the VM operation and restart the VM after movement. The processor resources of the VM, i.e. the virtual instruction processor can be stopped and restarted by controlling the assignment of the real instruction processor to the particular VM. The input/output operation performed asynchronously with the instruction processor is also likely to update the main memory, and must be suspended in operation. A forcible suspension of the asynchronous operation under way would make the restarting thereof difficult. This has posed the problem of how the asynchronous operation
Oyamada Kenichi
Sato Masaru
Antonelli Terry Stout & Kraus LLP
Follansbee John
Hitachi , Ltd.
Patel Haresh
LandOfFree
System with virtual machine movable between virtual machine... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with System with virtual machine movable between virtual machine..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and System with virtual machine movable between virtual machine... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3266058